#!/usr/bin/env bash
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# $Id: loadbalancer.sh 9947 2010-06-25 19:34:24Z manuel $ $HeadURL: svn://svn.lab.vmops.com/repos/vmdev/java/patches/xenserver/root/loadbalancer.sh $
# loadbalancer.sh -- reconfigure loadbalancer rules
# @VERSION@

source /root/func.sh

lock="biglock"
locked=$(getLockFile $lock)
if [ "$locked" != "1" ]
then
    exit 1
fi

usage() {
  printf "Usage: %s:  -i <domR eth1 ip>  -a <added public ip address ip:port> -d <removed ip:port> -f <load balancer config> -s <stats ip ip:port:cidr>  \n" $(basename $0) >&2
}

# set -x

# ensure that the nic has the public ip we are load balancing on
ip_entry() {
  local added=$1
  local removed=$2

  if [ "$added" == "none" ]
  then
	added=""
  fi

  if [ "$removed" == "none" ]
  then
	removed=""
  fi

  local a=$(echo $added | cut -d, -f1- --output-delimiter=" ")
  local r=$(echo $removed | cut -d, -f1- --output-delimiter=" ")

  for i in $a
  do
    local pubIp=$(echo $i | cut -d: -f1)
    logger -t cloud "Adding  public ip $pubIp for load balancing"
    for vif in $VIF_LIST; do
      sudo ip addr add dev $vif $pubIp/32
      #ignore error since it is because the ip is already there
    done
  done

  for i in $r
  do
    logger -t cloud "Removing  public ips for deleted loadbalancers"
    local pubIp=$(echo $i | cut -d: -f1)
    logger -t cloud "Removing  public ip $pubIp for deleted loadbalancers"
    for vif in $VIF_LIST; do
      sudo ip addr del $pubIp/32 dev $vif
    done
  done

  return 0
}
get_lb_vif_list() {
# add eth0 to the VIF_LIST if it is not there, this allows guest VMs to use the LB service.
  local lb_list="$VIF_LIST eth0";
  lb_list=$(echo $lb_list | tr " " "\n" | sort | uniq | tr "\n" " ")
  echo $lb_list
}
fw_remove_backup() {
  local lb_vif_list=$(get_lb_vif_list)
  for vif in $lb_vif_list; do
    sudo iptables -F back_load_balancer_$vif 2> /dev/null
    sudo iptables -D INPUT -i $vif -p tcp  -j back_load_balancer_$vif 2> /dev/null
    sudo iptables -X back_load_balancer_$vif 2> /dev/null
  done
  sudo iptables -F back_lb_stats 2> /dev/null
  sudo iptables -D INPUT -p tcp  -j back_lb_stats 2> /dev/null
  sudo iptables -X back_lb_stats 2> /dev/null
}
fw_restore() {
  local lb_vif_list=$(get_lb_vif_list)
  for vif in $lb_vif_list; do
    sudo iptables -F load_balancer_$vif 2> /dev/null
    sudo iptables -D INPUT -i $vif -p tcp  -j load_balancer_$vif 2> /dev/null
    sudo iptables -X load_balancer_$vif 2> /dev/null
    sudo iptables -E back_load_balancer_$vif load_balancer_$vif 2> /dev/null
  done
  sudo iptables -F lb_stats 2> /dev/null
  sudo iptables -D INPUT -p tcp  -j lb_stats 2> /dev/null
  sudo iptables -X lb_stats 2> /dev/null
  sudo iptables -E back_lb_stats lb_stats 2> /dev/null
}
# firewall entry to ensure that haproxy can receive on specified port
fw_entry() {
  local added=$1
  local removed=$2
  local stats=$3

  if [ "$added" == "none" ]
  then
	added=""
  fi

  if [ "$removed" == "none" ]
  then
	removed=""
  fi

  local a=$(echo $added | cut -d, -f1- --output-delimiter=" ")
  local r=$(echo $removed | cut -d, -f1- --output-delimiter=" ")

# back up the iptable rules by renaming before creating new.
  local lb_vif_list=$(get_lb_vif_list)
  for vif in $lb_vif_list; do
    sudo iptables -E load_balancer_$vif back_load_balancer_$vif 2> /dev/null
    sudo iptables -N load_balancer_$vif 2> /dev/null
    sudo iptables -A INPUT -i $vif -p tcp  -j load_balancer_$vif
  done
  sudo iptables -E lb_stats back_lb_stats 2> /dev/null
  sudo iptables -N lb_stats 2> /dev/null
  sudo iptables -A INPUT  -p tcp  -j lb_stats

  for i in $a
  do
    local pubIp=$(echo $i | cut -d: -f1)
    local dport=$(echo $i | cut -d: -f2)
    local lb_vif_list=$(get_lb_vif_list)
    for vif in $lb_vif_list; do

#TODO : The below delete will be used only when we upgrade the from older version to the newer one , the below delete become obsolute in the future.
      sudo iptables -D INPUT -i $vif  -p tcp -d $pubIp --dport $dport -j ACCEPT 2> /dev/null

      sudo iptables -A load_balancer_$vif  -p tcp -d $pubIp --dport $dport -j ACCEPT

      if [ $? -gt 0 ]
      then
        return 1
      fi
    done
  done
  local pubIp=$(echo $stats | cut -d: -f1)
  local dport=$(echo $stats | cut -d: -f2)
  local cidrs=$(echo $stats | cut -d: -f3 | sed 's/-/,/')
  sudo iptables -A lb_stats -s $cidrs -p tcp -m state --state NEW -d $pubIp --dport $dport -j ACCEPT


#TODO : The below delete in the for-loop  will be used only when we upgrade the from older version to the newer one , the below delete become obsolute in the future.
  for i in $r
  do
    local pubIp=$(echo $i | cut -d: -f1)
    local dport=$(echo $i | cut -d: -f2)

    for vif in $VIF_LIST; do
      sudo iptables -D INPUT -i $vif  -p tcp -d $pubIp --dport $dport -j ACCEPT 2> /dev/null
    done
  done

  return 0
}

#Hot reconfigure HA Proxy in the routing domain
reconfig_lb() {
  logger -t cloud "Reconfiguring loadbalancer using $1"
  /root/reconfigLB.sh $1
  return $?
}

# Restore the HA Proxy to its previous state, and revert iptables rules on DomR
restore_lb() {
  logger -t cloud "Restoring HA Proxy to previous state"
  # Copy the old version of haproxy.cfg into the file that reconfigLB.sh uses
  cp /etc/haproxy/haproxy.cfg.old /etc/haproxy/haproxy.cfg.new

  if [ $? -eq 0 ]
  then
    # Run reconfigLB.sh again
    /root/reconfigLB.sh /etc/haproxy/haproxy.cfg.new
  fi
}

get_vif_list() {
  local vif_list=""
  for i in /sys/class/net/eth*; do
    vif=$(basename $i);
    if [ "$vif" != "eth0" ] && [ "$vif" != "eth1" ]
    then
      vif_list="$vif_list $vif";
    fi
  done
  if [ "$vif_list" == "" ]
  then
      vif_list="eth0"
  fi

  logger -t cloud "Loadbalancer public interfaces = $vif_list"
  echo $vif_list
}

mflag=
iflag=
aflag=
dflag=
fflag=
sflag=

while getopts 'i:a:d:f:s:' OPTION
do
  case $OPTION in
  i)	iflag=1
		domRIp="$OPTARG"
		;;
  a)	aflag=1
		addedIps="$OPTARG"
		;;
  d)	dflag=1
		removedIps="$OPTARG"
		;;
  f)	fflag=1
		cfgfile="$OPTARG"
		;;
  s)	sflag=1
		statsIp="$OPTARG"
		;;
  ?)	usage
                unlock_exit 2 $lock $locked
		;;
  esac
done

if [ "$addedIps" == "" ]
then
  addedIps="none"
fi


if [ "$removedIps" == "" ]
then
  removedIps="none"
fi

VIF_LIST=$(get_vif_list)


if [ "$addedIps" == "" ]
then
  addedIps="none"
fi

if [ "$removedIps" == "" ]
then
  removedIps="none"
fi

#FIXME: make this explicit via check on vm type or passed in flag
if [ "$VIF_LIST" == "eth0"  ]
then
   ip_entry $addedIps $removedIps
fi

# hot reconfigure haproxy
reconfig_lb $cfgfile

if [ $? -gt 0 ]
then
  logger -t cloud "Reconfiguring loadbalancer failed"
  #FIXME: make this explicit via check on vm type or passed in flag
  if [ "$VIF_LIST" == "eth0"  ]
  then
     ip_entry $removedIps $addedIps
  fi
  unlock_exit 1 $lock $locked
fi

# iptables entry to ensure that haproxy receives traffic
fw_entry $addedIps $removedIps $statsIp

if [ $? -gt 0 ]
then
  logger -t cloud "Failed to apply firewall rules for load balancing, reverting HA Proxy config"
  # Restore the LB
  restore_lb

  logger -t cloud "Reverting firewall config"
  # Revert iptables rules on DomR
  fw_restore

  #FIXME: make this explicit via check on vm type or passed in flag
  if [ "$VIF_LIST" == "eth0"  ]
  then
     logger -t cloud "Reverting ip address changes to eth0"
     ip_entry $removedIps $addedIps
  fi

  unlock_exit 1 $lock $locked
else
  # Remove backedup iptable rules
  fw_remove_backup
fi

unlock_exit 0 $lock $locked